Which entity in Kubernetes is responsible for the availability of the service outside?

In Kubernetes, the entity responsible for external service accessibility is of type Service with LoadBalancer or NodePort, as well as the Ingress object.

• Service (LoadBalancer) — automatically creates an external load balancer (if supported by the cloud provider) and provides an external IP for accessing the service.
• Service (NodePort) — opens a fixed port on all cluster nodes, through which the service can be accessed externally.
• Ingress — a more flexible object that manages external HTTP/HTTPS access, allowing configuration of routing, SSL, and other rules.

The choice depends on the infrastructure and access requirements. Usually, LoadBalancer is used for simple access, while Ingress is suitable for more complex scenarios.